Latch mechanism



Patented Apr. 2, 1940 LATCH MECHANISM Allyn Moore Shaffer and JohnBurton Hatchet, Los Angeles, Calif.

Application September 4, 1935, Serial No. 39,109

6 Claims.

Our invention relates to an improved latch mechanism by means of which adoor, window, or hatch, etc., can be closed noiselessly in place ofslamming it shut.

A further object of our invention is to provide a latch mechanism bymeans of which a door, window or hatch, etc.. may be tightly andsecurely closed, against either rattling or leakage, by the operation ofthe latch mechanism itself without the necessity of slamming orotherwise forcing it shut.

Another object of our invention is to provide a latch mechanism by meansof which a door may be closed and the latch member engage the latchsocket even though the operating means of the latch mechanism is in theposition it normally occupies when the latch member is in the extendedor closed position.

A further object of our invention is to provide a latch mechanism inwhich the latch member is slidably and swingably moveable, and isslidably moveable independent of the operating means of the latchmechanism.

Another object of our invention is to provide a latch mechanism, thelatch member of which in closing is moved sidewardly and outwardly andupon engagement with the latch socket exerts a force thereagainsttending to close said door.

Still other objects and advantages of our inventlon will be made evidenthereinafter.

In the accompanying drawing forming part of this application, we haveillustrated one preferred form of embodiment of our invention. in whichdrawing similar reference characters designate corresponding parts andin which:

Figure 1 is a sectional view of the latch mechanism with the doorclosed.

Figure 2 is a perspective view illustrating one way of connecting thelatch member, links and operating arm together.

Figure 3 is a sectional view showing the latch member in a withdrawnposition.

Figure 4 is a sectional view showing the position of the latch mechanismas the door is about to be closed by manual operationof the operatingmeans.

Figure 5 is a sectional view showing the position of the latch mechanismwhen the door is being closed with the operating means of the latchmechanism in the closed position.

Referring to the drawing, a latch member I, a latch link 2, andoperating link 3, a stub arm 4, and an operating arm 5 are located in ahorizontal plane between the bearing surfaces 6 and 1 of a door 8. Apart of the edge 9 of the door 8 is cut out to allow for the movement ofthe latch member I, and part of the edge 8 is bent at right angles andcurved as shown in the drawing to provide a guide means Ill.

The wall II is provided with a wear plate l2 and part of the wall II andthe wear plate l2 are cut out to provide a latch socket II, which isadapted to be engaged by the latch member I.

The outer end of the latch member I is curved as shown in the drawing inorder to facilitate its movement in and out of the latch socket l3 andfor other reasons which will be made evident hereinafter.

Connected to the inner end of the latch member l are the outer end oflatch link 2 and the upper end of operating link 3. The inner end oflatch link 2 is connected to the outer end of stub arm 4. The stub arm 4is adapted to slide in and out between the flat bearing surfaces 6 andI4, and is held in the outward or normal position by means of a springor similar mechanism IS, the outward movement of which is limited bymeans of stops l6.

The lower end of the operating link 3 is connected to the outer end-- ofthe operating arm 5 which slides in and out between the bearing surfaces1 and H. The connection between the latch member I. the latch link 2,and the operating link 3, the connection between the latch link 2 andthe stub arm 4 and the connection between the operating link 3 and theoperating arm 5 may be of any convenient type which in each case allowsthe free rotation of the connected parts around a common axisperpendicular to the plane of their movement.

The operating arm 5 is held in its outward or normalposition as shown inFigure 1 by means of a spring la, the other end of which is connected tothe side 9 of the door 8. The other end of the operating arm 5 isconnected to the door levers l9 by means of link 20, bell crank 21 andcross shaft 22.

The latch member I, the latch link 2. the operating link 3, the stub arm4, the springs l5 and i8, and the operating arm 5 move in a planeparallel to that of the drawing and are so constrained in any convenientmanner. as. for example, the flat surface 23 and another flat surfacebelow the plane of the drawing not shown).

When the door is closed, the latch member I. latch link 2 and the stubarm 4 are aligned as shown in Figure 1.

In opening the door 8 one of the door levers I I is depressed whichmoves the operating arm I in the direction indicated by the arrow inFigure 3. The operating arm 8 draws the operating link 3 sideward andcauses the latch member I to be withdrawn sideward and inward at anangle essentially as shown, pivoting around the guide means It anddisaligning the latch memher I and the latch link 2. The connectionbetween the latch means I and 2 and the operating link 3 moves inwardand sideward because of the rotation of the latch link 2 about the outerend of the stub arm 4 (which remains stationary) and the movement of theoperating arm 5.

In closing the door one of the door levers I9 is depressed so that theend of the latch member I will not engage the wear plate I2. A moderateforce is applied to the door in order to partially close it, and whenthe door is brought into the position shown in Figure 4, the operatinglever I9 is released. The operating arm 5 is then moved in the directionshown by the arrow in Figure 4 because of the action of the spring I8which reverses the previously described motion in opening the door. Theoutward movement of the operating arm 5 is transmitted through theoperating link 3 to the latch member I, forcing the latch member I intothe latch socket I3 with a slidably swinging motion, levering againstthe edge 24 of the latch socket I3. Thus the latch member I acts as alever to exert a considerable force between the edge 24 of the latchsocket I3 and the bearing surface 6, thereby levering the door tightlyshut against the buiTer 25.

As shown in Figure 5, when the door is slammed or pushed shut withoutdepressing one of the door levers I9, the outer end of the latch memberI engages the wear plate l2, which forces the latch member I, the latchlink 2, and the stub arm 4 substantially as a unit in the directionindicated by the arrow in Figure 5, compressing the spring I5. When thedoor reaches a position in which the latch member I can enter the latchsocket I3, the spring I5 forces the stub arm I, the latch'link 2 and thelatch member I outward, substantially as a unit, forcing the latchmember I into the latch socket I3, and the entire latch mechanism intothe position shown in Figure 1. In the inward motion above described theoperating link 3 pivots about the outer end of the operating arm 5(which remains stationary) thus causing the connection of the latchmemberl and the latch link 2 to be drawn slightly away from the surface6. but in the subsequent outward motion the connection returns to itsprevious position. The latch member I in returning to its normalposition exerts a slight leveraction somewhat similar to the leveraction exerted in closing the door by the operation of one of the doorlevers I9. but of course not to the same degree.

In the claims we have used the term latch bolt means to include thelatch member I and the latch link 2, and the term door to include adoor, window, hatch, or similar article.

Although we have described our invention with respect to certainparticular embodiments thereof, nevertheless we do not desire to belimted to the particular details shown and described except as clearlyspecified in the appended claims, since many changes, modifications andsubstitutions may be made without departing from our invention in itsbroader aspects, which may be found useful in many other applicationsthereof.

We claim:

1. In a latching device of the class described the combination of alatch bolt means including a pair of toggle members, said latch boltmeans being movable into a retracted position by disaligning said togglemembers; operating means positively connected to said latch bolt meansfor moving said toggle members between aligned and disaligned positions,and resilient means yieldingly supporting said latch bolt means andpermitting said latch bolt means to be moved into a retracted positionby force applied tgthe end of the bolt means, said operating meanscausing; the toggle members to be slightly disaligned when the latchbolt means is forced into retracted position by the aforesaidapplication of force and causing the toggle members to be realigned whenthe latch bolt means is returned to its normal position by saidresilient means.

2. In a latching device of the class described the combination of: alatch member in a door, said latch member being one arm of a toggle andsimultaneously slidably and swingably movable in a plane to which thelamb edge of said door is substantially normal; and operating means forslidably and swingably moving said latch member in a curved path into aretracted position, said operating means comprising a slidable operatingmember and a link connecting the operating member to the latch member,said latch member being resiliently supported to permit the retractionof said latch member independently of the retraction of said latchmember by said operating means and without moving the slidable operatingmember.

3. In a latching device of the class described the combination of: alatch member in a door, said latch member being one arm of a toggle andsimultaneously slidably and swingably movable in a plane perpendicularto that of the door upon breaking of the toggle; operating means forbreaking the toggle for slidably and swingably moving said latch memberin a curved path into a retracted position; said latch member being alsoslidably movable into a retracted position along with the second arm ofthe toggle independently of the operation of said operating means.

4. In a latching device of the class described the combination of alatch member simultaneously slidably and swingably movable; operatingmeans for simultaneously slidably and swingably moving said latch memberin a curved path into one fully retracted position and. in which themajor portion of the movement is swinging; said latch member being alsoslidably and swingably movable into a second fully retracted positionand in which the major portion of the movement is sliding.

5. In a latching device of the class described the combination of: alatch member in a door, said latch member being one arm of a toggle, thesaid toggle being substantially in a straight line when the latch memberis in extended position, the other arm of said toggle being yieldinglysupported to permit said latch member to be re tracted withoutsubstantially disaligning said toggle; and means connected to the jointof said toggle for operating said toggle in a plane to which the jambedge of said door is substantially normal.

6. In a latching device of the class described the combination of: alatch member in a door which is one arm of a toggle and which is movableinto a latch socket of the door jamb; a guide means, and operating meansfor moving said latch member outwardly and pivotably around said guidemeans, so that the outer part of said latch member is moved outwardlyand sidewardly and upon engagement with the wall of said latch socketexerts a force thereasainst forcing the door shut, said latch memberbeing resiliently supported to permit the retraction of said latchmember independently at the retraction of said latch member by saidoperating means upon

